import os.path
from PIL import Image

blank = Image.new("RGBA", (640,443))

list = ("2011_09_26_Mon/20110926_", "2011_09_27_Tue/20110927_", "2011_09_28_Wed/20110928_", "2011_09_29_Thu/20110929_", "2011_09_30_Fri/20110930_", "2011_10_01_Sat/20111001_")

for e in list:
  for h in range(0,24):
    for m in range(0,60):
      filename = "%s%02d%02d.jpg" % (e, h, m)
      if not os.path.exists(filename):
         print filename
         blank.save(filename)

